Mackerel with lentil, turnip and apple slaw

1. Toast ½ tsp fennel seeds in a dry pan until fragrant, then lightly crush with a pestle and mortar. Put the egg yolk and mustard in a large bowl and use a balloon whisk to mix until creamy. In a small jug, combine the vinegar, oil and 1 tbsp water, then slowly drip into the egg yolk mixture, whisking continuously; season. Heat the lentils according to the pack instructions, then add to the dressing with the turnips, carrot, apple, most of the chives and the crushed fennel seeds.

2. Heat the grill to medium-high and line a baking tray with foil. Using a pestle and mortar, crush the remaining ½ tsp fennel seeds with the peppercorns and a pinch of sea salt flakes. Sprinkle over the mackerel fillets, then put on the lined tray, skin side up, and use a sharp knife to score the skin in 3 places. Grill for 2-3 minutes until the flesh is almost all opaque; turn over and cook for 1 minute, until cooked through and opaque. Serve the mackerel with the slaw, scattered with the remaining chives.